Kurtwood Smith. He claims to be the only Kurtwood on Earth.
Iggy!!!
Assuming Mr. Pop made it legal at some point.
And how about an entire band named Ramone? What are the chances? Did they make it legal?
And if you don’t believe him he’ll put his foot up your ass.
Flo & Eddie had a riff about how Yngwie J. Malmsteen uses his middle initial so he won’t get confused with all the other Yngwie Malmsteens in the music business.
Moon Unit, Dweezil, Ahmet, and Diva Zappa.
Johnette Napolitano of Concrete Blonde?
Alanis Morisette?
Soleil Moon Frye, star of “Punky Brewster”?
Oprah is the only Oprah I know of.
Madonna ditto.
There’s also Savion Glover, whose mother made up the name as a variation on “savior.”
However, I do know a five year old boy whose mother named him Savion, inspired by Mr. Glover.
I always thought it was his stage name, but Prince Rogers Nelson is his given name.
Treat Williams
Powers Booth
Keannu Reeve.
(Not really an actor, but…}
Sheryl Crow
Tori Amos
Ravi Shankar
What about Tori Spelling?
I’m pretty sure that none of those are unique.
I think that professional athletes should be included, since they are really just entertainers. My favorite is D’Brickashaw Ferguson. His older brother’s name is Edwin. How do you name one kid Edwin, and the next one D’Brickashaw?
Nevermind, it’s explained here: D'Brickashaw Ferguson - Wikipedia
There are lots of singers in Turkey named Ahmet, I bet. One of them who I used to have an album of is named Ahmet Özhan.
Speaking of Oprah, what about Stedman?
And if he finds another one, he’ll put his foot up the guy’s ass. 
That’s so he can claim sole ownership of the Kurtwood derby, which makes its wearer the least dumbassed man on Earth.
Diamanda Galás.
Just read through her Wikipedia entry and it appears to be her real, legal name.
Is Uma Thurmond a given name?